A bit, but I’m still not sure what your concrete questions are. Maybe I can approach it from a more general angle. You wonder how an anarchist society would concretely deal with certain situations. That’s a bit unfair, because one of the principle things about an anarchist society is that there is no one predetermined way to deal with anything. People will figure out the best ways based on self-interest, trial and error, and market forces. It’s not necessary, or even desirable, to punish wrongdoers, it is only necessary to protect one’s self from them, including extracting restitution if necessary, and, only secondarily, deprive them of the means to do more wrong.
Lets look at a very high-level abstract view of the dynamics in an anarchist system to illustrate the non-centralized, non-punitive way of “dealing” with wrongdoers.
Government is a heirarchy. Law flows from a root node at the top to leaf nodes at the bottom. It’s a one-way process, with only a very weak and indirect feedback mechanism in the form of voting, and to a limited extend civil disobediance (including things like “cheating” on taxes, or “evading” them). Note that I have nothing against heirarchy per se, only that I think it is inappropriate to a context where coercion is a potential factor.
Society in general, on the other hand, is a distributed network (less so lately, though that is a different issue). Through this network flows all the benefits of society - trade, information, resources, assistance, social relations, etc. There is no one root node - no single source for things - and there are few or no leaf nodes, or true sinks for what travels over the network. The feedback here is intense. Benefits propogate through the network, with some attenuation, strengthening the network as a whole. This then redounds indirectly to the benefit of the source of the original benefit. Harm does the same thing, and the feedback works the same.
Any single node’s ability to benefit from the network is a function of its connectivity to it. More connectivity means more “inputs”, more of the benefits - as well as the harms - of society flow through it. It also means more outputs, that node is able to affect the network more strongly, for both good and bad. A node, or collection of nodes, that is isolated from the network due to few or no connections, is limited in both how the network can affect it, and how it can affect the network. This isolated node receives relatively little benefit, but on the other hand can do relatively little harm.
In a network where connection can be made or broken - or strengthened and weakened - cheaply, the network organically orients itself toward beneficial nodes, and organically routes around damage. Those connections from which an individual node receives the most benefit will be strengthened, and those from which an individual node recieves harm will be weakened, or severed all together. Those nodes that provide little of either will neither grow nor shrink significantly. This does not require any node to know the ultimate source of the benefit or harm, only to judge the benefit or harm of the immediate neighbors to which it is directly connected. Any of those nodes may not provide any benefit or harm directly, but to the extent it propogates the benefit or harm done by others, it’s connections will be strengthened or weakened accordingly.
Now take this social network and make it an anarchist one by taking law and defense out of the heirarchal and allowing individual nodes to provide it to the network. The same dynamics will apply. Those who are beneficial - just law, effective defense - will have their connections strengthened. Those who provide harm - murderers and those who protect them, for instance - will have their connections weakened. You - a murderer - along with any defense agency foolish enough to protect you, will find yourselves increasingly isolated. The effect of this will be a reduction of the resources you have available to cause harm, but that will not be the purpose of it. The purpose will be for each individual node to weigh the cost and benefit of a given connection, perhaps one far removed from your direct influence, and act accordingly.
An intermediate node, perhaps your defense agency, will face the choice between harm coming from one side, and the loss of connectivity by self-preserving nodes on the other side. They may choose your side of the bargain, but no matter, the network will protect itself, and you can do whatever you want in your increasingly smaller world.
Of course, should you try to preserve your connections by force, more deliberate action may become necessary - your neck may become the point at which the connecion is severed. But in any case, it is not necessary to have a single decision maker, nor for anyone to have the explicit goal of punishing you. They don’t even need to know you exist. And the benefit to you, the murderer, in all this is that your isolation is unlikely to be absolute. There will be some few nodes who may choose to remain connected to you, for whatever reason (friendship, familial relations, business dealings), while limiting the propogation of your harm so as not to endanger their outward-facing connectivity. Should you then have an epiphany - or merely see yourself isolated beyond your tolerance - and decide to start providing benefit or at least ceasing to harm your still connected neighbors, you have a channel through which to slowly re-establish your place in the network.